An Integrated Circuit (IC) with compromised hardware security may reveal sensitive information. Conventional hardware security techniques may use cryptographic protocols to provide security. In cryptographic protocols, secrecy may be provided by trapdoor mathematical functions and digital keys, which may make the protocols resilient to algorithmic attacks. However, digital hardware security keys may be attacked in a number of ways including side-channel, electromigration, imaging, and fault injection.
Physically unclonable functions (PUFs) may be used in a number of security tasks. In PUF-based security, the underlying identification may not be in a digital format; instead, the identifiers may be analog variations of the phenomena. This may result in physical systems with behavior that is stable and that is very difficult to physically replicate in another PUF—even another PUF of the same design—due to their complex analog structure. In practical implementations, PUFs may take the form of a separate circuit within an IC.